Southern Company's Plant Bowen in Cartersville, Georgia. Coal-fired power plants would lose out under an international climate agreement. Photo: Reuters/Chris Baltimore

The Obama administration is working to devise a “hybrid” approach to an international climate change agreement -- one that compels countries to slash their greenhouse gas emissions but doesn’t force them to sign a legally binding treaty. The strategy would allow the United States to act on climate change without needing approval from Congress, the New York Times first reported on Wednesday.

Governments around the globe have struggled for more than two decades to find a way to keep planet-warming gases out of the atmosphere. Efforts have largely focused on crafting an enforceable legal document requiring nations to burn fewer fossil fuels and stop deforestation. The United States, however, has consistently maintained that a global treaty would never pass the U.S. Senate, where a two-thirds majority is required by the Constitution for ratification. Senators have historically rejected international efforts in general, preferring to keep laws domestic, and Republican lawmakers have grown increasingly allergic to climate-related measures.

“Four to five years ago, it wasn’t as widely understood that [the Senate] is a real obstacle for the U.S. government,” Nat Keohane, vice president for international climate at the Environmental Defense Fund and a former economic adviser to the Obama administration, told International Business Times. “But that’s shifted. The international community is starting to understand that this isn’t just an excuse [for inaction].”

With the world’s governments nowhere nearer to forging a binding treaty, climate negotiators are warming up to new tactics. As President Barack Obama steps up his own domestic climate efforts in his second term, the U.S. approach could have a strong shot at the United Nations-led climate talks in Paris next year, Ann Carlson, the Shapiro professor of environmental law at UCLA, said in an interview.

“It puts the U.S. in a different negotiating position than it’s been in over the past several years,” she said. She pointed to the Environmental Protection Agency’s June proposal to cut carbon pollution from existing power plants, as well as new provisions to restrict emissions from newly built facilities. Automakers are now required to increase the fuel economy of cars and light-duty trucks, and similar measures for heftier vehicles are pending.

“Trying to figure out how to actually have a ‘politically binding’ treaty has become much more salient,” Carlson said.

Under the “hybrid” climate approach, countries would agree to enact domestic climate change laws, as well as make voluntary pledges to reduce greenhouse gas emissions. Progress on those pledges could be tracked and measured in an international system; countries that fall behind would be singled out, Obama’s climate negotiators told the New York Times.

This “naming and shaming” component is similar to the “trade policy review” mechanism used by the World Trade Organization, Joshua Meltzer, a fellow in global economy and development at the Brookings Institution, explained. In the WTO, each country’s trade policy is reviewed by the leadership and other member countries, and policies considered unfair or illegal can be challenged. “No government likes to be held up in front of the world as not meeting any of its commitments,” he said.

Whether the Obama strategy can work -- and how well -- hinges on a handful of factors that have yet to be finalized. “The legal form of the treaty … is not the only thing that matters, in terms of effectiveness,” Keohane said. “It’s the more boring and technical infrastructure stuff that really counts.” That includes developing an accounting system to measure, review and verify emissions reductions, as well as providing incentives for governments to participate and comply with voluntary targets.

The sheer size of countries’ climate change commitments is similarly critical. Scientists have called for limiting global warming to about 2 degrees Celsius above preindustrial levels, though some say the world is already well on track to surpass that. “The real question is how ambitious are those targets, and how much does it have an impact on current behavior?” Thomas Heller, executive director of the Climate Policy Initiative, said. “Does it really add up to a trajectory that limits climate risk to the levels that a lot of people are talking about?”

Negotiators will likely mull such details next month at the annual United Nations General Assembly meeting in New York, where delegates will gather at a parallel climate change meeting to try to make progress on a deal. A United Nations climate summit is planned for Lima, Peru, this December to draft the agreement, which negotiators then hope to finalize in Paris in December 2015.

Meltzer said that news of the Obama approach “is a positive signal of the seriousness of the administration in trying to do a deal in Paris, and the amount of groundwork that’s going on now to prepare the space for a successful outcome.”